Abstract
Crystallization of amorphous solids under proper heat treatment conditions has witnessed great progress in recent years because it can be used to produce extremely fine nanocrystalline materials. In this paper, microstructures on a large variety of length scales of the nanocrystalline material crystallized from the amorphous phase by furnace heat treatment are extensively examined based mainly on our past research work in this field. The morphology, size, crystal lattice structure and hyperfine structure of nanocrystallites are studied by means of transmission electron microscopy, quantitative X-ray diffraction as well as transmission Mössbauer spectroscopy. The atomic arrangement and the vacancy-like defects in the grain and/or interface boundary of nanocrystalline materials are investigated by means of high resolution electron microscopy and positron lifetime spectroscopy. The basic structure unit heredity as well as the defective structure heredity between the nanocrystalline material and its mother amorphous phase is summarized.
